Differential Response to Handling Stress by Florida, Northern, and Hybrid Largemouth Bass

Abstract

Abstract Two electrophoretically identified parental strains of largemouth bass representing Micropterus salmoides salmoides, the northern, and M. s. floridanus, the Florida, subspecies and their reciprocal F1 hybrids were examined for responses to 12–24 h of net confinement. No differences in plasma glucose or chloride concentrations were observed in quiescent fish among the four strains grown in separate ponds to 78–120 g. Florida and hybrid largemouth bass had significantly higher plasma glucose and lower plasma chloride values after 24 h of confinement than northern strain fish. The Florida and one hybrid strain began to die before net confinement ended. Florida fish were the least tolerant of all strains to net confinement regardless of rearing or experimental conditions. After 7 d recovery from net confinement, 12% of the Florida fish were alive compared to 96% of northern fish and 31–81% of the hybrids.